shRNA suppresses heparanase expression in gastric cancer cells. A: The gastric cancer SGC-7901 cells were transfected with pGenesil-1, pGenesil-scrambled, and pGenesil-HPA. The transfection efficiency was monitored by the enhanced green fluorescent protein (EGFP) reporter within these vectors. The stable subclonal cells were screened by G418 selection; B: RT-PCR and real-time quantitative PCR indicated that stable transfection of empty vector (mock) and scrambled shRNA did not affect the mRNA level of heparanase. However, heparanase mRNA was significantly decreased in the stable shRNA-transfected cells; C: Western blot indicated that stable transfection of heparanase-specific shRNA, but not of scrambled shRNA or vector (mock), resulted in decreased heparanase protein expression in SGC-7901 cells. The symbol (a) indicates a significant (P < 0.05) decrease from parental cells. Experiments were performed in triplicate with essentially identical results.